Role of Hydration on the Electronic Transport through Molecular Junctions on Silicon
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- 作者：Nicolas Cl茅ment ; David Gu茅rin ; St茅phane Pleutin ; Sylvie Godey ; Dominique Vuillaume
- 刊名：The Journal of Physical Chemistry C
- 出版年：2012
- 出版时间：August 23, 2012
- 年：2012
- 卷：116
- 期：33
- 页码：17753-17763
- 全文大小：561K
- 年卷期：v.116,no.33(August 23, 2012)
- ISSN：1932-7455
文摘
Molecular electronics is a fascinating area of research with the ability to tune device properties by a chemical tailoring of organic molecules. However, molecular electronics devices often suffer from dispersion and lack of reproducibility of their electrical performances. Here, we show that water molecules introduced during the fabrication process or coming from the environment can strongly modify the electrical transport properties of molecular junctions made on hydrogen-terminated silicon. We report an increase in conductance by up to 3 orders of magnitude, as well as an induced asymmetry in the current鈥搗oltage curves. These observations are correlated with a specific signature of the dielectric response of the monolayer at low frequency. In addition, a random telegraph signal is observed for these junctions with macroscopic area. Electrochemical charge transfer reaction between the semiconductor channel and H+/H2 redox couple is proposed as the underlying phenomenon. Annealing the samples at 150 掳C is an efficient way to suppress these water-related effects. This study paves the way to a better control of molecular devices and has potential implications when these monolayers are used as hydrophobic layers or incorporated in chemical sensors.